Mercury and other vapor electric lamp



April 14, 1925,

F. REYNOLDS MERCURY AND OTHER VAPOR ELECTRIC LAMP Filed April 16. 1921 lNl/E/V Tb)? e W {a m K m, k. M M

F V a Patented Apr. 14, 1925.

1,533,900 FICE.

FBEDERICK auvnotns'or WALKERVILLE-ON-TYNE, ENGLAND, .sss euoaor omi- HALF TO THE SILICA SYNDICATE LIMI A COMPANY OF GREAT BRITAHW.

MERCURY AND OTHER TED, OF WESTMINSTER, LONDON, ENGLAND,

VAPOR ELECTRIC LAMP.

Application filed April 16, 1921. Serial No. 462,054.

- T 0 all whom it may concern:

Be it known that I, FREDERICK REYNOLDS, a subject of the King of Great Britain, re" siding at 14 Rosewood Crescent, Walkerville-omTyne, in the county of Northuinberland, England, have invented new and use ful Improvements in Mercury and Other Vapor Electric Lamps, of which the following is a specification.

This invention relates to mercury, and other, vapor electric lamps.'of the open, or atmospheric, type; such, for instance, as those described in the specifications of Brit ish Letters Patent Nos. 5596 and 21834 A. D. 1908 and No. 1 1587 A. D. 1911, the said lighting tube and receptacles, being composed of anysufiiciently refractory transparent material, such as quartz-glass.

The present invention provides an improvement in such lamps, whereby certain disadvantages thereof, as they have been hitherto constructed, are overcome and the life of the lamp consequently lengthened, the improved lamp being not only more ellicient in action, but also simpler and cheaper to manufacture, and one which can be more readily transported than is the case with the lamps of the said type as at present n use.

A lamp constructed in accordance with my present invention presents the following improved features The receptacles at either end of the lighting tube (which receptacles contain mercury, or other suitable vaporizable material employed, which however I will presume to be mercury) into which dip the wires for the electric current, are each provided with a closure which is tight against the escape of mercury, but not against the escape of air or gas, which if given off will be able to escape from the lamp. The closure is effected as follows: The receptacle at each end of the lighting tube, (or at one end only f not required at both ends) is prov ded with a tube of quartz glass, or other suitable refractory material through which is passed a molybdenum, tungsten, or other suitable refractory metal wire, which is to be connected with the electric sup 1y circuit. vThe extension is then heate to plasticity, and a joint is made by closing the plastic material round the wire, either by mechanical or at. mospherical pressure, so as to make a oint which is tight against the escape of the mercury, or other metallic vapourizable m'aterial resistant to interior pressure or external tension, proof against heat, but permitting the escape of air, or gas.

A single displacement chamber only is necessary, this being at one end of the lamp, but a second receptacle, permanently filled with mercury, is employed at the otherend as a means of securing a good contact for the leading-in wire, and to'provide the necessary cooling surface. 7

It has been proposed to employ a oonstriction in the lighting tube at the point where the mercury is to be broken in the lighting tube when starting the lamp to facilitate this starting by making it easier .to break the mercury. It has also been suggested to use a similar and separate constriction in the lighting tube at the point where the end of the .arc leaves the mercury at the negative electrode, or receptacle, for the purpose of raising the temperature of the mercury at this end to that of ,the' mercury at the positive end. I have found that in the lighting tube of a lamp of the open, or atmospheric, type, it is possible to combine these two functions in one single constriction and thus simplify the construction and reduce the electrical resistance of the lamp.

As a safeguard against the air, or gas, not escaping sufiiciently rapidly from the receptacle which receives displaced mercury as aforesaid, I may introduce a fine bore U-shaped tube, or its equivalent, with one leg opening to the exterior of the lamp and the other leg opening to the upper part of the interior of the said receptacle, through which tube, air, or gas, will rapidly escape;

but owing to the small bore of the said U- sha -d tube and its disposition, mercury wil not pass through the said U-shaped, tube whatever position the lamp may be in.

I will describe, with reference to the accompanying drawing, two forms of the lamp constructed in accordance with this invention. As these, although they are of difierent shape, present the same, or equivalent, features. I will in describing the drawings refer to corresponding parts in all the figures by the same letters of re fcrence.

Figure 1 is'& side elevation in longitudilamp.

In both cases represented by Figures 3 and 4, the container of the lamp comprises a lighting tube (marked 2), which may be straight, or of other suitable shape; such, forexample,'as the shapes shown in the several figures.

Each end of the said tube 2, is connected to, and is in communication with, a receptacle for the mercury, these receptacles be ing respectively marked 3 and 4. They are shewn as being somewhat cylindrical in general formation, and they have, as shown in Figures 1 and 2, smaller receptacles, 8 and 9, rising from them respectively and terminating, at the top, in tubular projections, marked 5 at one end and 6 at the other end, through which tubular projections the conducting wires 1, for the electric current, are

passed into contact with the mercury. These wires are of such character and are so sealed into the said tubular projections 5 and G that the joint is tightagainst the passage of mercury under slight pressure, but not against the passage of air, or other gas. An auxiliary conducting wire 7, is similarly sealed in the tubular projection 9 from the additional receptacle 9" in communication by the opening 9 with the small receptacle 9, and thence with the receptacle the said wire 7, being connected to a heating device of any usual, or suitable, kind, surrounding the tubular extension 10, from the lighting tube 2, in such manner that, when the level of the mercury rises in the extension 9, of the receptacle 4, the said mercury comes into contact with the body of mercury, shown in the small container 9 into which the auxiliary conducting wire 7 dips, and the heating resistance surrounding the extension -10 is short-circuited. Electrical connections as above described are indicated in the small scale diagram Figure 5 but it will be understood these and also the mercury contact heater cut-out connections will, in practice, be arranged in any convenient manner. The sealing of the wire 7 in the tubular projection 9 allows of the passage of air, or gas, but not of mercury under slight pressure, as in the case of the wires 1 and their seals.

.' During the ope "ation of the lamp, bubbles of air, or other gas, or gases, disengaged from the mercury in the receptacles 3 and 4, will pass out of the lamp through the seals at 5, 6, and 9.

At that part of the lighting tube 2 which is provided "with the tubular extension 10, is a constricted portion '2 which is conessential.

tinned towards, or nearly up to, the receptacle 3. The heating-coil which surrotmds the tubular extension 10 serves to vapourize the mercury therein for the purpose of starting' the operation of the lamp.

The end of the lighting tube 2, where it communicates with the receptacle l, is shewn,in Figure 1, as being closed by the division plate at 11, except for the small holes, seen at 12, which may,if two in numher for example, each be about half a millimetre in diameter. These holes act in known manner as a damper, or battle, to the flow of mercury contained in the lamp and prevent the are opening out too quickly when the lamp is first started, and they also serve to prevent, or retard, displacement of the mercury when the lamp is in transit, or is moved out of normal working position.

I do not limit myself to the precise forms and details shewn in the several figures, as it will be evident that modifications can be made in'the shape and arrangements, as will be understood-from the drawing, where the parts in Figures 1 and 2, and in Figures 3 and 4, which correspond with each other are marked with the same letters of reference, the essential parts being similar in both cases.

In the form shewn in Figures 3 and l, the receptacle 4 has its longer dimension in a line with the lighting tube 2 instead of at right angles thereto, as in the form Figures 3 and a, and in place of the holes 12, in the division plate 11, there is a division plate 11 perforated at 12 between the reccptacles =1- and 9 In Figures 3 and 4: one of the main conducting wires 1 is brought, from the side, through the tubular pro ection 6 into the mercury in the receptacle -.l-, and a U-shapcd tube 13, open at both ends, is employed tor the purpose of giving an extra'outlet for air from the extension 9 of the reservoir 4, although this addition is not In this modification the auxiliary leading-in wire 7 is led through the tubular projection 9 into the small container 9" with a bulb at its lower end having holes 9 in it, the said wire 7 dipping into the mercury in the said bulb. When the lamp lights up, the mercury (similarly to what occurs in the form of the lamp Figures 1 and E2) rises in the extension 9 to the level of the holes 9 in the bulb, and passes into the said bulb and makes elcctrical contact with the mercury therein and therefore also with the wire 7 and cuts out of circuit the heating coil around the pro jection 10 from the li hting tube 2.

The bend in the llghting' tube, where it enters the receptacle 4, as shown in Figure 3, is for the purpose of steadying the light as hereinbefore explained.

Although I have referred to mercury as being the vapourizable material employed,

it will be understood that other suitable vapourizable material can be used in the lamp if desired.

\Vhat I claim is 4 1. A vapor electric lamp of the atm0spheric type, having a lighting tube, a chamber at only the lower end thereof for displaced Vaporizable liquid, a chamber at the upper end of said tube and filled with said vaporizable liquid, said lighting tube being constricted to assist in the striking of an are at the starting of the lamp, said constriction being of such extent and so located that the liquid at the negative and of the lamp remainsin the constriction during the play of the are, said constriction being of such cross section that at the negative end of the lamp the cross sectional area of the liquid upon which the arc plays is less than that upon which the arc plays at the positive end of the lamp, the relation between said areas being such that the temperatures of the opposed faces of the li uid electrodes upon which the arc plays at 1ts op osite ends, are substantially equal, and condensation at the negative electrode is thus avoided.

communicating at one end with sai 2. .A vapor electric lamp having at an otherwise sealed end, atubular glass extension for a lead wire, a refractory metal lead wire entering the lamp through said tubular extension and havin a joint therewith sealed by the compression of the glass, while in plastic condition, against the passage of the vaporizable liquid of the lamp, but permitting the escape of gas therethrough.

3. In a vapor electric lamp, a lighting tube having a chamber for displaced vaporizable liquid, and a fine-bore U-shaped dpassage her, and open at its other end to the exterior of the lamp, the diameter of said U- shaped passage being such that while gas is free to escape the-rethrough, the esca cham- 

